Preparation of composite Al2O3-TiO2 particles from organometallic precursors and transformations during heating

Brugger, Pierre Alain; Mocellin, A.

doi:10.1007/bf01106567

Cited by 24 publications

(17 citation statements)

References 8 publications

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“…However this compound is not stable below 1180 °C; it decomposes into TiO 2 (rutile) and α-Al 2 O 3 at low temperatures, although metastable Al 2 TiO 5 can be preserved at room temperature. It has been prepared by conventional ceramic processing of oxides, , chemical vapor deposition, and sol−gel processing. − Formation of Al 2 TiO 5 occurs above 1300 °C. The low expansion results from microcracking that occurs during cooling and confers low mechanical strength .…”

Section: Introductionmentioning

confidence: 99%

Nonhydrolytic Sol−Gel Process: Aluminum Titanate Gels

et al. 1997

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The efficiency of the nonhydrolytic sol−gel process based on the condensation between metal chlorides and metal alkoxides has been studied in the preparation of aluminum titanate gels. Solutions of aluminum and titanium precursors in the ratio Al/Ti = 2 gave gels with the same metal ratio. The structural evolution of the samples is unusual; they directly crystallize at T > 600 °C into metastable pseudo-brookite β-Al2TiO5 and are reluctant to decompose into stable TiO2 (rutile) and α-Al2O3 at 1150 °C. This behavior must be connected to the high homogeneity of the samples originating from the nonhydrolytic sol−gel process.

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Section: Introductionmentioning

confidence: 99%

Nonhydrolytic Sol−Gel Process: Aluminum Titanate Gels

et al. 1997

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“…Binary systems can be obtained e.g. by mixing of sols of different metals [ 19 ] or by the cohydrolysis or copolymerization of mixtures of alkoxides [20,21].…”

Section: Synthesis Methods and Principlesmentioning

confidence: 99%

Ceramic nanostructure materials, membranes and composite layers

1989

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Synthesis methods to obtain nanoscale materials will be briefly discussed with a focus on sol-gel methods. Three types of nanoscale composites (powders, membranes and ion implanted layers) will be discussed and exemplified with recent original research results. Ceramic membranes with a thickness of 1-10 ktm consist of a packing of elementary particles with a size of 3-7 nm. The mean pore size is about 2.5-3 nm. The preparation routes are based on sol and sol-gel technologies. The pores can be modified by liquid as well as by gas deposition techniques. This leads to modification of the chemical character and the effective pore size and gives rise to microstructure elements well below the size of the pores (3 nm). The modification of ceramic surface layers with a thickness of 0.05-0.5 lam by ion implantation and annealing procedures yields amorphous or strongly supersatured metastable solid solutions of e.g. Fe203 (or TiO2) in zirconia-ynria solid solutions or of very finely dispersed metal particles in the ceramic surface layers. Particle sizes are of the order of 2-4 nm. Both types of structures have interesting transport, catalytic and mechanical properties.

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“…Esta metodología ha sido usada con gran éxito, inicialmente en el campo de las cerámicas, en la preparación de compósitos en forma de polvos no aglomerados monodispersos de A1203-TiOa para obtener finalmente titanato de aluminio ó bien composito de corindón-rutilo bajo condiciones controladas de sinterización (68,69).…”

Section: Formación De Compósitosunclassified

“…Este comportamiento se repite en las muestras calcinadas a 7oo.C (figura 5.9). El estado amorfo o microcristalino de los Ala-TiQ calcinados a 5oo.c y 7oo.C se ha atribuido a la formaci6n una solución dlida o un 6xido mixto real (68,95,19).…”

Section: Losunclassified

“…A partir de los resultados anteriores se pueden establecer dos posibles hip6tesis: a) El primer modelo se designará como "TS" (titania depositada en la superficie), esto es, el Ti4+ no está entrando a la estructura de la bayerita, sino que queda en la superficie ocupando huecos 6 vacancias, lo que provocaría que el T i a cristalizara en anatasa y la temperatura de cristalización dependería del contenido de Tia+ (68). Este modelo, en principio, está relacionado con el de la monocapa (15), el cual ha sido propuesto para los comp6sitos formados por y -A l a recubierta con TiG.…”

Section: Hipbtesisunclassified

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Propiedades estructurales, texturales y ácido-base de óxidos metálicos mixtos de Al2O3-TiO2

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Preparation of composite Al2O3-TiO2 particles from organometallic precursors and transformations during heating

Cited by 24 publications

References 8 publications

Nonhydrolytic Sol−Gel Process: Aluminum Titanate Gels

Nonhydrolytic Sol−Gel Process: Aluminum Titanate Gels

Ceramic nanostructure materials, membranes and composite layers

Propiedades estructurales, texturales y ácido-base de óxidos metálicos mixtos de Al2O3-TiO2

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